When the kids are out of school, summertime field trips are the best way to break up the monotony of playground days. But with about three months to plan for, excursions can add up (in time and in your bank account). We tracked down ways to trek around town without breaking your family budget.

MY Denver Card: Denver kids ages five to 18 have year-round access to the 23 recreation centers and 29 pools in the city. If your child already has a Denver Public Library card, that card also becomes the MY Denver Card.

Lookout Mountain Nature Center Programs: Camps are expensive—and some of your little ones may not be ready to spend the night away from home. The Lookout Mountain Nature Center offers dozens of free classes for kids of all ages. Options include Preschool Nature Nuts and Junior Naturalists, a nature journaling club that guides kids in drawing outdoors.

Douglas Country Libraries Adventure Pass: If you live in Douglas County, reserve free passes to the Butterfly Pavilion, Dinosaur Ridge, the History Colorado Center, and the Plain Conservation Center. There are a finite number of passes available for each day, but you can reserve up to 30 days in advance. All you need is a Douglas County library card.

Free admission dates around town:

Clyfford Still Museum (per county):

Adams County, June 11

Arapahoe County, June 18

Boulder County, July 2

Broomfield County, July 16

Denver County, July 30

Douglas County, August 13

Jefferson County, August 27

Denver Art Museum:

June 7

July 5

August 2

Denver Botanic Gardens:

June 3 (Chatfield)

August 4 (Denver)

August 5 (Chatfield)

Denver Children’s Museum:

June 3, 4-8 p.m.

July 1, 4-8 p.m.

August 5, 4-8 p.m.

September 2, 4-8 p.m.

Denver Museum of Nature and Science:

June 2

June 30

July 20

What did we miss? Comment below or on our Facebook page to fill us in on other frugal summer outings.

—Image courtesy of Shutterstock